Page 18 - Process Plant Portable Buildings - CCPS Safe Work Practice

Incidents

Buncefield Oil Storage Terminal - Explosion and Fire

Description: On 11 December 2005, an explosion occurred at the Buncefield Oil Storage Terminal near Hertfordshire,
U.K. causing 43 reported injuries. The initial explosion occurred near one large storage tank that led to further
explosions and fires eventually involving 23 large storage tanks. The initial explosion registered 2.4 on the Richter
Scale and the resulting fire was described as the “largest incident of its kind in peacetime Europe.” The incident
investigation evidence suggested that one storage tank’s level monitoring and high-level trip system failed during
filling, causing about 330 tons of unleaded gasoline to spill from the overfilled tank through its roof vents. This formed a
large flammable vapor cloud that reached an ignition source and exploded with tremendous energy.
Discussion: A special review of the Buncefield explosion mechanism and damage assessment to buildings was
undertaken. The most intense blast wave caused significant building damage within 0.5 km and injuries to witnesses.
Onsite buildings housing non-essential personnel were located within the blast zone that received considerable
damage, such as two warehouses, a cafeteria and two security buildings. Damage assessment of onsite buildings
yielded an estimated 8 tons of TNT equivalent explosion energy at the flammable gas cloud center. Damage to offsite
domestic buildings occurred to a distance of about 4 km. This incident emphasizes the susceptibility of traditional, light
construction portable buildings to VCE events.

Buncefield Incident Report (HSE)

15 SAFE WORK PRACTICE, PROCESS PLANT PORTABLE BUILDINGS